Notes on this puzzle
Mine Finder #5212 hides 40 mines in a 16×16 field of 256 cells, a density of 15.6%. Every safe cell here can be decided by looking at one number at a time.
The board starts with 75 cells already uncovered, 35% of the safe ground, so the first deduction is waiting for you. Under the cover, 53 safe cells touch no mine at all, 95 show a 1 and 51 show a 2; 17 cells carry 3 or more, and the highest number in the field is 4. 12 of the mines lie along the border of the field. Corners hold 1 of them; a corner cell has only three neighbours.
Where to beginWhen two numbers share most of their neighbours, subtract one from the other.